Condenser



D- K. DEAN March 15, 1932.

CONDENSER Filed Oct. 16, 1930 3 Sheets-Sheet lNVENT 42m fall aim 5/3ATTORNEY March 15, 1932. D, K, DEAN. 1,849,057

CONDENSER Filed Oct. 16, 1930 s Sheets-Sheet s 'INVENTOR 6d WWW PatentedMar. 15, 1932 UNITED STATES PATENT OFFICE.

DION K. DEAN, or RAHWAY, NEW JERSEY, AssIeNO T'O FOSTER wHEELERcoRrO-RATION, OF NEW YORK, N. Y., .A CORPORATION or NEW YORK CO DENSERApplication filed October 16, 1930. Serial No. 489,052.

For example, in a circular shell condenser in which the rows, ifcontinued, would meet at a common low point on the vertical center lineof the condenser, the lanes near the vertical center line areconsiderably longer, and even several times longer, than the lanes atthe lateral parts of they condenser. It will width, the resistances ofthe lanes will differ widely since, with a conduit ofgiven'crosssectional area, resistance to v flow is directly proportionaltothe length. Furthermore, the tubes are usually spaced the samedistance apart in the rows and therefore, in any one transverse sectionor in the condenser as a whole, the condensing capacity of a lane may besaidto be proportional to the lengthof the lane. v

Thus the condition exists that the lanes of greater cooling'capacityhave greater resistance to flow. That is, a lane of small con-1 (lensingcapacity will pass a great amount of steam due to its low resistance.Putting it another way, the steam short-circuits through the short lanesand the long lanes do not get enough steam. This is the opposite rela- 0tioncooling capacity to lane resistance a which should exist.Considerable steam passes to the vacuum pump by short-circuit-v ing; thelong lanesdo not get enough steam to utilize their full condensingcapacity; and the efficiency of the condenser is lower than what shouldcorrespond to the actual condensing capacity. v o

It is the object of my invention to obviate these disadvantages-by soarranging the tubes that the lanes are supplied with quantities of beseen that if these lanes havethe same mean carrying the cooling fluid;for example,

steam proportional to their condensing. capacities. To accomplish this,I make the longer lanes wider than the shorter lanes. Furthermore, inthe preferred embodimentof the invention, I relate the widths of thelanes to their lengths, as will hereinafter more clearly appear. 7

The invention will be understood on consideration of the followingspecification taken; in conjunction with the accompanying drawingsforming a part thereof and on which: A I g Fig. 1 is a diagrammaticillustration of the invention; I

Fig. 2 is a transverse sectional view of a condenser of the type havingrows radiating from a common point and embodying the invention, thesection being taken on the line 22of-Fig. 8; and. i

Fig. 3 is. a central longitudinal section of the condenser shown in Fig.2.

The diagrammatic showing of Fig. 1 illustrates va condenser inaccordance with the invention. It may be assumed that the condenser isof uniform cross-section throughout its length. The vapor to becondensed is supplied at the top through conduit 2. The shell 3 enclosesa condensing chamber through which extend longitudinal cooling tubes 4water. The tubes are arranged in vertical rows and are spaced the samedistance apart vertically. Between the rowsof tubes are vertical lanes,some of which are lettered A, B. C and D. Due to the-configuration ofthe shell,the lanes are ofdifferent lengths. a Lane A. is the longestand lane D is the shortest. The condensed vapor leaves the condenserthrough. conduit 5. p I I Assume first that the lanesare of equal width.Assume also that the tubes are of the same temperature at any givencross-section. The condensing capacities of the lanes are then directlyproportional to the number of tubes on the sides of the lanes. The tubesbeing equally spaced in the rows, the condensing capacities are thenproportional to. the lengths'of thalanes. LaneA-has, for example, agreater condensing capacity than lane D. Consequently more steam shouldpass into lane A than into lane D. However, with lanes of equal width,less steam will pass into lane A than into lane D because lane A islonger than lane D and therefore offers greater total resistance to flowof fluid therethrough than does lane D (other factors be ing constant),in accordance with the fundamental physical laws of flow of fluids inconduits. As herein used the term total resistance means totalresistance for a given flow of steam.

But, with lane A wider than lane D, as shown in Fig. 1, the resistanceof lane A is less per unit length than lane D. Assume first that lane Ais so much wider than lane D that the total resistance to flow in thelanes is equal. Then approximately the same amount of steam would flowinto the two lanes. This, however, would not give the result I am toaccomplish since I wish to have less steam enter lane D than lane A.Consequently I increase the width of lane A beyond the point where thetotal resistance is the same and to a point where the total resistanceof lane D is so much greater than the total resistance of lane A that asmaller quantity of steam flows into the shorter lane than into thelonger lane.

Obviously, the relative widths of rows can be determined by experiment.The obj ective is attained if, in a condenser where the pressure dropthrough the lanes is the same, as in Fig. 1, the steam at the ends ofthe different lanes is of the same temperature. This indicates whatmight be termed transverse equality of steam penetration, which is theobjective of the invention.

However, the widths can, by making certain assumptions, be calculatedwith a reasonable degree of certainty and without the trouble incidentto experimentation by trial and error. Therefore, I will outline themathematical aspect of the invention.

Assuming that all the steamis condensed in a lane at the exit terminalof the lane, we may say that the volume of steam passing an elementarysection in the lane is a function of the distance from such elementarysection to the exit terminal of the lane. f, in Fig. 1, we select anelementary section AL, the volume of steam passing the elementarysection is a function of the distance L from the exit terminal of thelane. Stating it mathematically, AQ=L, where AQ, is the quantity passingthe elementary section and 7c is a constant.

The velocity of steam at the elementary section is then IcL where a isthe width of the lane. c

The friction or pressure drop across the elementary section varies asthe square of the velocity and as the length of the elementary section.Expressing this mathematicallywe have:

If this equation is integrated to obtain the total friction drop weobtain:

powers of the lengths of the lanes. Expresslng this mathematically, withreference to lanes A and B in Fig. 1:

Thus, having given the width of one lane, it is possible to calculatethe widths of the other lanes to find thevalues which will result in thelanes receiving varying amounts of steam proportional to theircondensing capacities with equal friction drops through 1 the lanes.

It is to be understood that the above'calculationdoes not apply to allcondensers but has been worked out for condensers having the rowsarranged vertically in parallel. However, by using the fundamentalsunderlying the above calculation, it should be possible to work out theproper relation for any condenser.

While the condenser shown in Fig. 1 is not of circular section, it willbe seen that the same considerations would apply if the crosssection ofthe shell were circular and the tubes were arranged in vertical rows. 7

In Figs. 2 and 3 -I have shown the invention applied to a condenser ofthe type having converging lanes. The shell of the condenser isdesignated 1O. A plurality of longitudinally extending coolingtubesextend within the shell and are supported at their ends and suitablyfixed in tube sheets 12 and 13. Cooling fluid such as water is adaptedto enter the condenser through the inlet water box 14: and, afterpassing through the tubes 11, to leave the condenser through outletwater box 15. Vapors enter the condenser through vapor inlet 16 and thecondensate which collects in the bottom of the condenser passes throughan opening 17 into a trap 18 which is connected by a conduit 19 to asuitable tail pump, not shown. Gaseous fluid is removed from thecondenser through conduit 20 which is connected to a suitable air pump,not shown. The lower portion of the condenser may be considered as anair cooler, cooled by the tubes 21. 1

The arrangement of the tubes 11 is in accordance with the presentinvention. The tubes are arranged in rows which radiate from a commonpoint 0. The rows are arranged at different angles relative to eachother to alter the widths of the lanes so that the total resistances ofthe respective lanes shall be in inverse relation to their lengths as inthe arrangement shown in Fig. 1. Asshown in the drawings the laterallanes which are shorter are narrower so that their resistance to flow isgreater.

The angularity, that is, the angle between any two adjacent rows, whichdiffers in all the lanes, can be determined mathematically along thesame lines as above indicated with reference to Fig. 1. The lengths ofthe lanes are the lengths from their inlets to the beginning of the aircooler section indicated by the dash-and-dot line A'C. Since the widthof any lane varies as it goes downwardly, this factor must be taken intoaccount. Width is then a function of the distance from the point 0.Working this out mathematically I obtain the following equation for therelative angularities of the lanes:

2d log In this equation L isthe distance from the generating point 0 tothe point where the steam path begins, and d is the distance from thegenerating point to the end of the lane, that is, to the line AO. Thisformula is based on the assumption that the distance between tubes inany row is the same and that the pressure at the inlets and outlets ofthe lanes is the same.

It will be seen that in accordance with the invention the rows arearranged so that the total resistances of any two lanes are in inverserelation to the lengths of thelanes, and that the width of a longer laneis increased with respect to the width of a shorter lane beyond thepoint where the total resistance is the same and to a point where theresistance of the shorter lane is so much' greater than the resistanceof the longer lane that a smaller quantity of steam flows into theshorter lane than into the longer lane and so that the proportion ofsteam'entering the respective lanes is in accordance with the condensingcapacities of the lanes so that the steam penetration in the lines willbe equal.

It will be clear that the invention is not limited to the particulartypes of condensers indicated.

Furthermore, my. invention, which provides transverse. equalization ofsteam penetration, may be combinedv with any known arrangements forproviding longitudinal equalization of steam penetration. In case ofusing a condenser having. a number of.

straight but-may zigzag. The invention will i apply to such structure,it being necessary to determine the effective widths of the lanes. Withequal spacing of tubes in irregular rows, the row'sbordering a shorterlane should,'in acco-rdance with the invention, be closer together thanthe rows bordering a longer lane. Furthermore,the rows may be ofunifornicurvature and either parallel converging or otherwise related.

What I claim is: I

1. A condenser comprising a shell having a steam inlet and an outlet anda plurality of tubes extending in the same general direction to carry acooling medium through the shell, the flow of steam being generallytransverse to the tubes, the tubes being, arranged inrows to providelanes in which the steam fiows, the form of the shell and thearrangement of tubes being such as to provide lanes of differentlengths, and said rows being spaced different distances apart to providelanes of different widths along the lengths thereof, the width of arelatively long lane being greater than the width of a relatively shortlane.

2. A condenser comprising a shell having a steam inlet and an outlet anda plurality of tubes extending in the same general direction to' carry acooling medium through the shell, the flow of steam being generallytransverse to the tubes, the tubes being arranged in'rows to providelanes in which the steam flows, the form of the shell and thearrangement of tubes being such as to provide lanes of differentlengths, and said rows being spaced different distances apart to providelanes of different widths, the width of a relatively long lane beinggreater than the width of a relatively short lane by an amount 7 beyondthat at which the vtotal resistance to flow in the lanes is equal and toan amount where the total resistance of the shorter lane steam flowsinto the shorter lane than intothe longer lane.

' 3. A surface condenser having rows of' tubes forming lanes ofdifferent lengths, the rows bordering a shorter lane being closertogether along the lengths thereof than the rows bordering a longerlane. 5 l. A surface condenser having rovvs of tubes forming lanes ofdifferent lengths, the rows being arranged difierent distances apart,the Width of a relatively long lane being greater than the Width of arelatively short lane and the relation cit-widths being such that thelanes Will receive steam in accordance with their condensing capacities.

5. A surface condenser having rows of tubes forming lanes of difierentlengths, the rows being arranged different distances apart, and thespacing of the rows being such that the total resistance to flow indilierent lanes is in inverse relation to their condensing capacities. v6. A condenser comprising a shell having a steam inlet and an outlet anda plurality of tubes extending in the same general direction to carry acooling medium through the shell, the flow of steam being generallytransverse to the tubes, the tubes being arranged in rows to providelanes in which the steam flows, said rows having intersecting lines, theform of the shell and the arrangement of tubes being such as to providelanes of diflerent lengths, and said roWs being spaced at difierentdegrees of angularity to provide lanes of difierent Widths atcorresponding radial distances, the Width of a relatively long lanebeing greater than the Width of a relatively short lane.

7. A condenser comprising a shell having a steam inlet and an outlet anda plurality of tubes extending in the same general direction to carry acooling medium through the shell, the flow or" steam being generallytransverse to the tubes, the tubes being arranged in rows to providelanes in which the steam flows, said rows being arranged in intersectinglines, the form of the shell and arrangement of tubes being such as toprovide lanes of difierent lengths, and said rows being spaced atdifferent degrees of angularity to provide lanes of different Widths atcorresponding radial distances, the Width of a relatively long lanebeing greater than the Width of a relatively short lane by an amountbeyond that at Which the total resistance to flow in the lanes is equaland to an amount where the total resistance of the shorter lane is somuch greater than the total resistance of the longer lane that a smallerquantity of steam flows into the shorter lane than into the longer lane.

In testimony whereof I hereunto aflix my signature. 7

' DION K. DEAN.

